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L^NIVERSITY OF ILLINOIS BULLETIN 

IssuEij Weekly 

Vol. Xiy July 23, 1917 No. 47 

[Entered as second-class matter December 11, 1912, at the post-office at Urbana, Illinois, under 
the Act of August 24, 1912] 



Department of Household Science 



Fats and Oils in Cookery 
Cooking Temperatures 



By 
Anna W. Williams, M.A. 

And 

Cora E. Gray, M. S. 




PUBLISHED BY THE UNIVERSITY OF ILLINOIS 
URBANA 



5«- 



<^^^ 



PIJEFACE 

The subject of fats and oils is a very broad one. This bulletin 
does not pretend to cover the entire subject, but deals chiefly with the 
uses and abuses of these foods in cookery. Knowledge of the whole 
subject of fats and oils is incomplete, and much of the burden of expla- 
nation rests with the chemists who are seeking to solve problems from 
which the housewife will some day derive practical benefit. At 
present, however, little chemical information of practical use is at 
hand, and it seems worth while to collect the facts that are obtainable, 
and to set them forth for the use of those who may need them. 

A knowledge of the various types of fats and the possibilities of ■ 
substituting one for another is very essential, particularly in the ' 
present crisis. From an economic standpoint such knowledge may be 
of great aid, and it may prove an even greater aid from the standpoint 
of nutrition. As in the case of a lowered supply of wheat it becomes 
necessary to learn how to use other food materials which answer the 
samq purposes in the body, so in the case of a changing supply of fats 
one must know the possibilities of those fats Avhich can be obtained. 
Also, in this day of cpnstantly changing prices, the type of food that 
has been used today may be beyond one's means tomorrow. Hence, 
the necessity ha:s arisen for a wider knowledge of the subject of food 
values and food supplies. It' is the aim of this bulletin to give some 
help in this direction. 



FATS AND OILS IN COOKERS' 

SOURCES AND CLASSES 

Fats are derived from both the animal and the vegetable king- 
doms. A few decades ago, the former source was the chief one used 
by the people of this country, but of late years the latter has been 
drawn upon more extensively. The chief animal fats used as food are 
cream, butter, lard, and suet. The common vegetable fats are olive, 
cottonseed, corn, and nut oils ; there are on the market, also, com- 
pounds of animal and vegetable fats and some products, such as 
Crisco, made by treating an oil with hydrogen. In the home, other 
fats, such as beef and bacon drippings and chicken fat, are obtained 
by the cooking of meats. These, if carefully saved and judiciously 
used, will lower considerably the cost of fat in the household. 

As in other food supplies, the accessibility determines the amount 
of any kind to be used, and the fact will always remain that the avail- 
able and the cheapest foods are the ones which will be employed. It 
would be foolish to counsel the ivoman with plenty of fresh cream and 
butter at her immediate command to purchase olive oil at one dollar 
per quart. It is equally foolish to recommend cream at fifty cents per 
quart to the undernourished factory girl. Each consumer must study 
the possibilities and limitations of hei>-own source of supply, and mast 
act accordingly. « v 

CHEMICAL AND PHYSICAL PROPERTIES 

All fats and oils are composed of the elements carbon, hydrogen, 
and oxygen. These elements are combined in such a way as to form 
compounds of glycerin and fatty acids called glycerids. That is to 
say, all fats and oils contain glycerin, but the fatty acid may differ, • 
and upon the acid depends the melting, point and other distinguishing 
characteristics of the compound. The compound is called a fat if its' 
melting point is so high as to make it solid at ordinary temperature, 
and an oil if its melting point is so low as to make it liquid at ordinary 
room temperature. The three most important fatty acids are palmitic, 
stearic, and oleic. The first two are much alike, both the acids and 
the fats in which they predominate being hard substances of high melt- 
ing point, said chemically to be saturated. Vegetable fats and oils 



4 University of Illinois Bulletin [July, 

contain more palmitic than stearic acid, while the contrary is true of 
fats and oils of animal origin. Oleic acid and the oils in which it 
predominates are quite different. Their melting point is low and they 
are chemically unsaturated. The hard tallow of beef and mutton con- 
tains glycerin combined with large amounts of stearic acid, some 
palmitic, and relatively little oleic. Lard contains a larger proportion 
of oleic acid compounds. Olive oil is almost entirely a glycerid of 
oleic acid. 

It has been found possible to change some oils into solid fats and 
to harden fats which were already solid by heating the oil under 
pressure with hydrogen, in the presence of a catalyst, such as nickel. 
The unsaturated fats, which are soft, take up hydrogen to form sat- 
urated, fats, which are less soft. These hydrogenized fats are coming 
to be more and more commonly used, and new forms under varied 
names are appearing constantly on the market. 

In the presence of moisture, fats become rancid on exposure to 
air, or warmth and light. This rancidity is developed by a process of 
oxidation and hydrolysis, and generally develops more readily in oils 
than in solid fats. 

Fats have different melting points, ranging from the oils which 
are liquid at ordinary temperatures and solidify below 0° C. to mutton 
fat, one of the hardest, having a melting point of 49°-50° C. High 
heat causes smoking. This is due to decomposition, altho some decom- 
position may occur at a lower temperature. A list of fats, with 
their smoking temperatures, is given below. The tests were made on 
one cup of fat in a small saucepan, six inches in diameter. 

Table 1. — Smoking Temperatures of Fats 



Kind of fat 


Smoking temperature 


Cottonseed oil (Wesson) 

Snowdrift 

Criseo 


degrees Centigrade 
225 
223 
217 




210 


Corn oil (Mazola) 

Lard 


208 
175 


Olive oil 


156 


Bacon fat 

Suet 


145 
117 



Katherine Blunt and Clara Feeney^ found the smoking tempera- 
ture of a fat to vary according to the amount of surface exposed, the 



'Journal of-Home Economics, Vol. VII, No. 10, p. 535. 



1917] 



Fats and Oils in Cooking 



amount of free acid, and the amount of foreign material present, such 
as particles of food or crumbs. The above smoking temperatures will, 
then, vary according to the size and shape of the utensil used, being 
lower for a wider pan and higher for a more narrow one, as in the 
former case the surface exposure is greater. They would also be low- 
ered by rancidity or repeated use of the fat, which means increased 
free acid, or by the presence of foreign particles. However, under 
similar conditions, the relation of the temperatures should remain un- 
changed. 

Some results of the work done by Blunt and Feeney follow. 



Kind of fat 


Smoking temperature 
in evaporating dish 

degrees Centigrade 
233 
232 
231 
221 
208 
207 
194 
190 
175 


Free acid, as oleic 


Cottonseed oil (Wesson) .... 

Snowdrift 

Crisco 


percent 
0.07 
0.06 
0.13 


Leaf lard 


0.15 


Butter fat 


0.28 


Leaf lard (heated 5 hours) . . . 
Bulk lard 


0.34 
0.51 


A much used lard 


O.Gl 


Olive oil 


0.92 







It may be seen readily that, while the temperatures in the two 
tables are not the same, nevertheless relatively they fall in the same 
order. The differences are to be explained by the fact that a larger 
and wider utensil was used in the first case than in the second ; conse- 
quently, smoking began at a lower temperature. This range in smok-. 
ing temperatures shows that the old time test of fat for frying, ' ' smok- 
ing hot, ' ' does not give the same temperature for all fats ; hence, other 
tests must be relied upon. The characteristics of a good fat for a fry- 
ing medium are : first, a high smoking temperature ; second, the smoke 
should increase slowly ; and, third, the smoke should not be irritating 
in character. The first smoke from olive oil, for example, is not irri- 
tating and it increases very gradually, so that at 300° C. it is by no 
means as disagreeable as is lard which starts to smoke at a higher tem- 
perature. The objections to fats which smoke readily are the irritat- 
ing odor and the impaired quality of the fat for further frying. 
Smoking is an indication of decomposition, and the fat which decom- 
poses most on heating can be used the fewest number of times. From 
this last standpoint, the cottonseed products are especially desirable 
as a medium for frying. 



6 University of Illinois Bulletin [Ju^ll, 

VALUE AS FOOD 

Fats and oils are of value in the diet chiefly because for a given 
weight they yield more energy than do any of the other foodstuffs. 
One gram of carbohydrate or of protein yields four calories of energy 
in the form of heat, but one gram of fat yields nine calories. For this 
reason, fats are of especial value to the manual laborer, to the person 
who works out-of-doors in cold weather, and to the thin or anemic 
person who has no reserve of fat in his own body. Some of the fats 
and oils, because of their greater degree of absorption from the 
digestive tract, are of greater value in giving energy than are others. 
Fats haAang low melting points have been found to be more completely 
assimilated than those having high melting points. ^ Therefore, olive 
or Wesson Oil and butter, which have low melting points, are to be 
chosen as foods that will be well absorbed, and hence the ones from 
Avhich the greatest fuel value will be obtained. Another factor which 
influences the digestion of a fat is the degree of its emulsification. Only 
emulsified fats are digested to any appreciable extent in the stomach, 
and the finer the emulsification the greater is the rapidity of digestion 
and absorption in the duodenum and, often, the greater is the complete- 
ness of utilization. Fats of milk and of egg are examples of this fine 
emulsification. 

Some people cannot digest large amounts of fat. This foodstuff 
delays the emptying of the stomach, retards the secretion of the hydro- 
chloric acid, and also promotes regurgitation thru the pylorus into 
the stomach, thus neutralizing the acid that is present there. All of 
"these may occur when foods are fried or sauted so as to absorb large 
amounts of fat, or when much fat is mixed thru the food as in very 
rich pastry. The retardation, in turn, gives an opportunity for l)ac- 
terial action in the interior of the food mass, resulting in a loss of food 
to the bodj' and also in the production of gases and even of poisonous 
substances. This is the explanation of much of the indigestion of 
which people complain after eating foods rich in fat. One other cause 
of difficulty in the digestion of fried foods is that the fat is frequently 
overheated during cooking and is thus doeoni posed into substances of 
an irritating character. For these reasons, jiastry and fried foods do 
not belong in the child's diet nor in that of the person witli a Avcak 
digestion. Neither should they be eaten frequently nor in large 
amounts by anyone. 



^Langworthy and Holmes, "Digestibility of t^ome Animal Fats," U.S. De- 
partment of Agriculture, Bulletin 310, ji. 21. 
H. C. Sherman, "Food Products," p. 389. 



1917] Fats axd Oils ix Cooking 7 

Osborne and Mendel and also McCollum and Davis^ have been 
making observations on the influence of natural fats upon growth. 
They have found that butter fat is valuable, not only because of the 
fuel value which it has, but also because it contains certain growth 
promoting constituents, not found in all fats. Beef fat also supplies 
these substances, but in a smaller amount. Egg yolk fat and cod-liver 
oil, too, belong in this list, but lard, almond, cottonseed, and olive 
oils, altho valuable foods, so far as known at present do not contain 
these special constituents. It is evident, then, that rich milk, cream, 
butter, eggs, fat beef, and cod-liver oil are of especial value in growth 
and also in eases of malnutrition. 

Fats vary in their cost. Often a less expensive fat answers the 
purpose as well as a more expensive one, and the question may be 
worth asking, "Are we paying too high for flavor?" The following 
table shows the prices (May, 1917) for some common fats. 

Table 2. — Prices of Some Commox Fats 



Name of fat 


Price per pound 


Olive oil 

4 ounce or Vi pint bottle , 

8 ounce or Yo pint can 


Mmj, 1917 

$1.20 
.(50 


16 ounce or 1 pint can 


.55 




.50 


Butter 


.52 


Oleomargarine 


.25 


Crisco 


.35 


Cottonseed oil (Wesson) 

Lard 


.29 

.30 


Home rendered lard (purchased at 18 cents 

per pound exclusive of fuel) 

Home rendered lard -1- gas 


.21 
.22 







The table shows not only the range in prices, but also the advis- 
ability of buying oils in the can rather than in bottles, especially when 
the bottles are small in size. The can is of additional advantage, as it 
shuts out the light, and light is a potent factor in the production of 
rancidity. The differences in price of olive oil according to quantity 
purchased are illustrative of similar differences to be found in pur- 
chasing most foods. The home rendered lard may be more or less 
expensive than an equally good grade of commercial lard according 
to the cost of fuel and the value of the housewife 's time. 



'Journal of Biological Chemistry, Vol. XVI. p. 423; Vol. XVII, p. 401; Vol. 
XX, pp. 379, 641; Vol. XXI, p. 179;' Vol. XXIII, p. 231 



8 University of Illinois Bulletin [July, 

The initial cost of a fat is not the only point to be noted. When 
used for shortening, a larger amount of one may be required than of 
another. As butter is only 85 percent fat while lard, oils, and Crisco 
are 100 percent, less of these is required than of butter. Again, in 
frying, more of some fats is absorbed than of others. In cooking 
doughnuts, different fats were found to be absorbed according to the 
following order: olive oil (least). Wesson Oil, Crisco, lard, lard and 
suet (most). More important still, from the standpoint of economy, 
is the question, ' ' Which fat can be used the greatest number of times ? ' ' 
This use depends primarily upon the decomposition temperatures. In 
general, such fats as lard or lard and suet, which give off most smoke 
at frying temperatures, can be used a smaller number of times than 
can those giving off less smoke, as Crisco or the oils. The care in heat- 
ing and the method of clarifying employed by the housewife also help 
to determine the number of times the fat can be used. Fat once over- 
heated until it smokes excessively can never be used as long as can 
the same fat not so overheated. However, Wesson Oil or Crisco do 
not gi\'^ off this heavy smoke until a very high temperature is reached, 
but lard decomposes so rapidly on slight overheating that much care 
is required to prevent it. 

The economy of substituting less expensive fats for those high 
priced luxuries can easily be seen. For example, one cup of mayon- 
naise dressing made of olive oil bought by the quart costs 27 cents, 
whereas if made of cottonseed oil, one cup costs 11.25 cents. Again, 
the substitution of one cup of oleomargarine for one cup of butter in 
a cake gave practically identical results and reduced the cost by 8.5 
cents. Partial substitution of Crisco might profitably have reduced it 
still further. In some cases, fats cannot be substituted thus, but often 
the question of substitution becomes merely one of flavor and must be 
determined according to one's taste and pocketbook. 

USES IN COOKERY 

Fats are used in cookery for three general purposes : first, to flavor 
or ta enrich foods, as in cooked salad dressing and white sauce, or as 
an emulsion in French dressing or mayonnaise ; second, as a medium 
for browning and cooking in sauteing or frying ; and third, as a short- 
ening agent in flour mixtures. From the fats available, the housewife 
must select one which imparts an agreeable flavor and a good texture 
for her purpose. 



1017] Fats and Oils in Cooking 9 

The following fats were tested recently in cooking experiments 
conducted in these laboratories : olive oil, Mazola, Wesson Oil, chicken 
fat, butter, oleomargarine, Snowdrift, lard, Crisco, suet, and bacon 
drippings. The flavor obtained is the first consideration. Olive oil 
gives, in all cases except in fried foods, a very pronounced and charac- 
teristic flavor. This, for salad dressing, constitutes its chief recommen- 
dation. Mazola, a corn oil, gives a flavor only a little less strong, but it 
is often not detected unless used in large amounts. Wesson Oil is prac- 
tically tasteless. Chicken fat has its own distinctive but mild flavor 
unless tried out at a high temperature ; in doughs and batters its use 
is ordinarily not evident. As an enriching or shortening agent, butter 
is generally used and directions for the substitution of other fats are 
concerned largely with methods of approximating the flavor and 
texture secured with butter. Oleomargarine, if of good quality and 
purchased of a reliable firm, may be used for the same purposes as but- 
ter, in all sorts of cooking, and it is difficult to detect even in mildly 
seasoned sauces. Snowdrift is a very white fat but one which easily 
becomes rancid. In these tests it was never satisfactory because of 
the strong, disagreeable flavor. Lard and Crisco, altho differing in 
source and smoking points, give somewhat similar results as shortening 
agents. Lard can almost always be recognized by a peculiar charac- 
teristic sensation in the mouth. Crisco gives somewhat the same sen- 
sation in the mouth as lard but to a lesser degree. It ordinarily has 
little flavor, altho after long standing it may become strong. Suet 
has a very limited use because it can practically always be tasted and 
its hardness gives an unpleasant texture. Bacon drippings are strong 
flavored, but are not for that reason necessarily useless. They should, 
however, be restricted to sauteing of those foods in which the added 
flavor is not objectionable. The consistency of cooked salad dressings 
and of mayonnaise, the color secured in sauteing or deep -fat frying, 
the texture of muffins, cakes, and pastry, vary somewhat with the kind 
of fat used, and these variations will be discussed later. 

COOKED SALAD DRESSING 

Recipes for cooked salad dressing usually call for butter or per- 
haps for olive oil, but cheaper fats may be substituted. Wesson Oil 
or oleomargarine can easily be used, but the taste of Mazola is imme- 
diately apparent and its presence must depend upon whether or not 
one likes the flavor it gives. Crisco and lard are possible altho the 
discriminating person detects them easily. Chicken and bacon fats 



10 University of Illinois Bulletin [July, 

are quite noticeable, but may be a desirable addition Avith a vegetable 
or a meat salad. Suet is disagreeable. The consistency varies so little 
with the different fats as to be quite unimportant ; so the selection of 
the fat depends upon the flavor imparted. In other words, any one of 
several common fats may be used for cooked salad dressings, especially 
if the combination is carefully considered. If, however, cooked salad 
dressing is made in large quantities and used from time to time for 
different salads, butter, oleomargarine, or Wesson Oil is best because 
of the flavor. 

FRENCH AND MAYONNAISE DRESSINGS 

For French dressing, olive oil is generally recommended but "Wes- 
son Oil or Mazola may be used. The difference between a dressing made 
with olive oil and one made entirely of Wesson Oil is the absence of 
the distinctive olive flavor rather than any added taste. Substituting 
Wesson for one-half the olive oil enables one to secure the flavor of the 
more expensive product and at the same time to lower the cost consid- 
erably. The presence of Mazola is very evident unless the dressing 
contains at least one part of vinegar to three of oil, so that for those 
who do not like a very tart dressing, AVesson gives the best results. 

For mayonnaise dressing. Wesson is a better substitute for olive 
oil than Mazola, for the flavor of Mazola is not sufficiently disguised 
by the smaller proportion of other ingredients. Chicken fat, especially 
the more oily portion, can be utilized, altho the flavor is evident. If 
one does not have an oil at hand, mayonnaise dressing may be made 
with washed and melted butter, oleomargarine, or melted Crisco ; half 
oil and half washed or unsalted butter give an especially well-flavored 
dressing of good consistency. 

WHITE SAUCE 

White sauce can be made easily with fats other than butter if the 
purpose for which it is to be used is kept in mind. For example, with 
finnan haddie the flavor of the partly smoked fish is so pronounced that 
almost any fat can be used in the sauce without being detected ; with 
creamed meats, the use of drippings is sometimes a desirable addition. 
Since white sauce is served hot and the proportion of fat is small, no 
variation in consistency is apparent. 

SAUTEING 

In sauteing, a golden brown color and a good flavor are the desired 
ends. The color usually depends upon the temperature and the time 



1917] Fats and Oils in Cooking 11 

of cooking, bnt it is sometimes heightened by the discoloration of the 
fat. Starch and sugar brown so easily that flour mixtures or meats 
rolled in bread crumbs acquire a good color whether the fat contributes 
to it or not, but some vegetables brown with such difficulty that a fat 
of low smoking point, as suet or drippings, gives a better appearance. 
Altho often recommended, butter burns so easily that, when it is 
used, it is difficult to avoid a very uneven color and often an unpleasant 
flavor. Better results are obtained with butter as well as with suet 
and drippings if some other fat of high smoking point, like Crisco or 
Wesson Oil, be substituted in part. Olive oil and Mazola give charac- 
teristic flavors which may or may not be liked. Wesson Oil is prac- 
tically tasteless, and consequently can be very generally used. More- 
over, because of its high smoking point, there is little danger of scorch- 
ing. Chicken fat, bacon, or other drippings often add an agreeable 
flavor to meats or vegetables, but they must be selected with care to 
avoid unpleasant combinations. Lard and Crisco are so nearly taste- 
less that like Wesson Oil they find wide use. Suet, because of its flavor 
and the unpleasant sensation left in the mouth when it cools even a 
little, is better used in small quantities or with other fats. 

DEEP-FAT FEYING 

In deep-fat frying, an even brown color and a pleasant flavor, with 
the minimum of fat absorption, make a good product. The color de- 
pends upon the character of the food and of the fat, but more especially 
upon the temperature and the time of cooking. The flavor varies with 
the fat used, altho the differences are much less than one might 
expect. For example, even Mazola and chicken fat give little taste 
to doughnuts and none at all to French fried potatoes sprinlded 
■\sdth salt. While strongly flavored fats need not ahvays be discarded, 
those with little flavor are safest for general use. The smoking point 
of fats also determines the quality of the flnished product, for Avhen 
fats smoke, decomposition is taking place at a rather rapid rate, pro- 
ducing an unpleasant flavor. Moreover, fats which have become dis- 
colored by decomposition do not produce as even a color in frying. 
Consequently, lard which is used "smoking hot" is less satisfactory 
than Crisco, Mazola, or Wesson Oil, which give no smoke at any ordi- 
nary cooking temperature. (See Table 1, page 4.) The high smoking 
point of chicken fat makes it especially desirable for frying, but it is 
not often obtained in the ordinary home in quantity sufficient for that 
purpose. Moreover, chicken fat is very much the best butter substi- 
tute for shortening and should be reserved for that purpose. 



12 University of Illinois Bulletin [July, 

Greasiness is somewhat dependent upon the kind of fat used but 
much more dependent upon the food to be cooked and the temperature 
employed. Rich doughs and batters become more grease soaked in fry- 
ing than those containing less shortening, and foods cooked at too low 
a temperature absorb a large amount of fat because the protecting 
coating is formed less quickly than at a higher temperature and because 
the material stays in the fat for a longer time. Doughnuts made with- 
out shortening absorb much less fat than those in which shortening is 
used. Because at least a small amount of fat is taken up in frying, a 
fat with little flavor and a high smoking point is best for general use. 
Of the fats used, Wesson Oil and Crisco fulfil the conditions best. 

SHORTENING 

DOUGHS AND BATTERS 

With doughs and batters, the kind of fat to be used varies with the 
amount required, for with the possible exception of butter, no one fat 
gives a uniformly good texture and flavor in all mixtures. Since dif- 
ferences produced in texture are neither marked nor important except 
in cakes and rich muffins, the choice in mixtures containing little fat 
is governed by flavor. In griddle cakes, any fat except olive oil can 
be used, but the griddle should be greased with one having little flavor. 
For muffins, butter gives the best flavor and the greatest tenderness, 
but oleomargarine or chicken fat produces an almost identical product. 
Crisco, lard, or Wesson Oil gives good results provided a little extra 
salt is added ; of the three, lard is the most easily detected. Mazola is 
too apparent to be desirable, and drippings and suet are so strongly 
flavored as to be impossible. For biscuits, the same fats may be used 
as for muffins except that the failure to increase the salt is more serious 
and that Crisco seems to produce a somcAvhat coarser texture. For the 
richer shortcake mixture, a fat with little flavor, like Crisco, lard, or 
Wesson Oil, is best with the exception of chicken fat. For l)oth bis- 
cuit and shortcake, to secure the best texture, oils when used should 
be mixed with the liquid rather than with the flour. 

CAKES 

With the exception of pastry, cake is the richest mixture used. 
For that reason, care is needed in the selection of the fat, but since the 
flavor is often disguised by extracts, spices, or chocolate, a compara- 
tively large number of fats are possible. 



1917] Fats and Oils in Cooking 13 

One of the characteristics of a good cake is tenderness. The 
influence of the mixing upon tenderness is well known, but varia- 
tions due to the kind of fat used are often not sufficiently empha- 
sized. The most tender cake is obtained with butter. This does not 
mean that a good cake cannot be made with other fats but merely 
that if two cakes are made from the same recipe and with the same 
method of mixing, one with butter and the second with some other 
fat, the one in which butter has been used seems the more tender. 
The nearest approach to the texture of a butter cake is obtained with 
chicken fat or oleomargarine. Contrary to what one might expect from 
the results with chicken fat, oils do not produce good cake. The cake 
seems dry and breadlike, Avhile if more fat is added, it becomes greasy, 
and if more liquid, coarse. Since butter is 85 percent fat and lard and 
Crisco, 100 percent, in substituting either for butter, to secure the same 
richness, the quantity should be reduced about one-eighth. Increasing 
the liquid slightly to allow for the moisture of the butter improves the 
texture. The amount of beating is, however, the most important 
factor, for beating increases the tenderness and the apparent richness 
of any cake. A butter cake made with the minimum of beating may be 
tender, but one with Crisco is dry and lacking in richness if beaten too 
little. To secure the best possible texture in substituting Crisco or 
lard for butter, the amount of fat should be decreased one-eighth, the 
liquid should be slightly increased, and care should be taken to beat 
the cak§ well. 

Butter gives not only the best texture but the best flavor also, and 
if it is used at all in baking, it should be for cake. The best substitute, 
from the standpoint both of flavor and texture, is oleomargarine or 
chicken fat wdth increased salt, and, as has been said before, the best 
use for the limited amount of chicken fat usually obtained in the home, 
is as a butter substitute in cakes. For a white cake, where it is desired 
to avoid all color, Crisco is the best shortening agent, if the precau- 
tions noted in the discussion of texture in cakes are observed. Lard 
tho often used, is more easily detected than Crisco and hence is less 
satisfactory. It can, however, be used safely with spices or any strong 
flavoring extract. Snowdrift, altho very white, is very apparent and 
unpleasant in flavor even in spice cake. The oils are not desirable 
because of the texture produced. 



14 



University of Illinois Bulletin 



[July, 



PASTKY 

For plain pie crust, lard gives the tenderest and flakiest product. 
A good crust can be secured with oils if they are properly handled but 
a mealy rather than a flakj^ texture is the result. Not more than one 
part of oil to four of flour should be used, and care should be taken to 
mix the oil and flour only slightly. Otherwise so little water can be 
added that the pie crust is very difficult to handle and crumbles to 
pieces when baked. Chicken fat gives a good crust but it should be 
handled like the oils. Butter produces a crust of delicious flavor for 
those Avho are willing to pay the price, but the texture is no better 
than with lard and often not so good. Sour cream when used in some- 
what larger proportion than the oils requires a little soda to neutralize 
the acid, but gives a very good quality of crust and one tasting much 
like a butter crust. No water can be used, as there is sufficient liquid 
in the cream. Oleomargarine gives a crust almost impossible to detect 
from one made Avith butter. A crust made with Crisco closely resem- 
bles one made with lard. Suet does not give a good texture and both 
suet and drippings are too strongly flavored to be desirable. 

SUMMARY 

The problem of the housewife in the use of fats and oils in cookery 
is largely one of understanding the possibilities and limitations of her 
particular supply, and of using that supply as economically as possible. 
This involves an understanding of the possible substitutions* of one 
fat for another, with some knowledge of their comparative costs. The 
following table shows the possible uses of the ordinary fats. 

Table 3. — Summary of Uses of Easily Obtainable Pats 



Kinds of fat 



Flavor 



Uses 



Olive oil 

Wesson Oil . . . . 

Mazola 

Chicken fat. . . 

Butter 

Lard 

Snowdrift 

Crisco 

Suet 

Bacon fat 

Oleomargarine. 



Strong 
Slight 

Fairly strong 

Mild 

Mild 

Mild 

Often strong 
Slight 

Strong 
Very strong 
Mild 



Uncooked salad dressings 
Deep-fat frying, salad dressings, 

shortening except cakes 
Deep-fat frying 
Shortening, especially cakes 
Shortening, except of plain pastry 
Shortening, especially of plain 

pastry 
Frequently too strong for use 
Sauteing, deep-fat frj'ing, short- 
ening 
Sauteing 
Sauteing 
Same as butter 



1917] Cooking Temperatures 15 

COOKING TEMPERATURES 

USES OF THE THERMOMETER 

No factor in the preparation of food so largely determines the 
results as does heat. Upon its proper application depends the texture 
and quality of a product and also the development of the finer flavors. 
Exact results can be obtained only by the use of accurate methods, 
and the thermometer furnishes the only really accurate method of 
determining the degree of heat that is being applied. Satisfactory 
results may be produced by the use of good judgment only, but 
good judgment requires repeated observation, training, and skill, is 
acquired slowly, and is dependable only after years of experience. 
Judgment, developed by experience, enables one to tell the time of 
day by the sun, but a watch is much more easily used and is a more 
accurate gage. 

Housewives employ many little devices which show their need of 
a definite measure for temperature. Thus a bit of flour or bread is 
browned in the oven, a small preliminary cake is baked, or a piece of 
bread is browned in hot fat in ' ' forty counts ' ' before frying croquettes 
or in "sixty counts" before frying doughnuts. The woman who uses 
gas learns to light the burner a definite time before putting her bread 
to bake, and then turns the flame off one-half or one-third. All of 
these devices show an attempt to obtain exact methods of applying 
heat. 

The chemical thermometers give very accurate results. They do, 
however, have the serious drawback of being easily broken and of re- 
quiring a hole in the top or side of the oven for their insertion. The 
mercury bulb should be as near as possible to the food being cooked, 
since the temperature at the top or at the side of the oven is not the 
same as in the center. If the thermometer is inserted thru the side, 
just below the grate, the bulb is then immediately below the food being 
cooked. These chemical thermometers can be had ranging from the 
six-inch 100° C. thermometers, Avhich may be inserted in a roast, up 
to those registering 300° C. and recording as high temperatures as are 
ever used in cookery. 

Thermometers on stands, which may be placed beside the bread 
or cake in the oven and which are less easily broken, may also be had 
in the Fahrenheit scale. These are sufficiently sensitive for ordinary 
purposes, as they record the temperature to within ten degrees of the 
chemical thermometer. They are especially satisfactory when used with 
an oven having a glass door. When used in a coal range and placed 



16 University of Illinois Bulletin [July, 

directly on the bottom of the oven, a temperature of approximately 
85° F. lower than the required gas oven temperature should be used 
because of the difference in the course of the heat in the two stoves. 

Stove manufacturers are recognizing the value of a heat gage 
and are putting thermometers on the outside of their ovens. Such 
thermometers are of considerable value and aid greatly in determining 
the temperature. Heretofore we have sought, in our laboratories, to 
record chiefly the temperature in the center of the oven, and have not 
relied to any extent upon thermometers which register the heat else- 
where. Since these thermometers on the outside seem to be most 
practicable and most easily observed, we m.ay, with profit, learn to use 
a slightly different set of temperatures based on their records. Start- 
ing with those temperatures taken at the center of the oven, we must 
make allowance for the fact that the outside thermometer will record 
the heat more slowly, and will register a temperature of about 50° F. 
lower than the thermometer in the center. 

The table on the opposite page shows the range of temperatures 
applicable in the preparation of foods, as worked out in these labora- 
tories. 

DISCUSSION OF TEMPERATURE TABLE 

Water is frozen at 0° C, but fruit ices or ice creams freeze at a 
lower temperature. Substances in solution lower the freezing point, 
and the more concentrated the solution, the lower the temperature re- 
quired to freeze it. Thus, a mixture may be prepared containing so 
much pulp and sugar that it is almost impossible, by ordinary methods, 
to freeze it. Under such circumstances, the remedy lies in diluting the 
mixture and adding more salt to the crushed ice. Three parts of ice 
to one part of salt ordinarily gives a sufficiently low temperature for 
freezing ices and ice creams, but adding more salt prodvices a still 
lower temperature. 

Water simmers before it boils. Tiny bubbles rise and break under 
the surface of the water, and some form about the edges of the pan. 
When water boils, however, the surface is completely agitated. Above 
sea level, the boiling point may be reached at 98° C. or 99° C. or lower, 
according to the altitude. Simmering temperature is used in the cook- 
ing of meat stews and of so called "boiled" meats. 

The boiling point of a sugar solution is higher than that of water, 
as substances in solution raise the boiling point. The temperatures 
given in the preceding table should be lowered 1° C. for every degree 
below 100° C. found as the boiling point of water. If the boiling point 
is 99° C, then fondant frosting is best at 112° C.. etc. Most satisfac- 



1917] 



Cooking Temperatures 
Table of Temperatures 



17 



Process 



Freezing of fruit ices (temperature of 

medium) 

Freezing of water 

Whipping of cream 

Butter-making 

Raising of bread (temperature of room) 
Cheese-making 

Coagulation of albumin 

Simmering of water 

Soft custards 

Double boiler, top part 

Boiling water at sea level 

Jellies (boiling point of water 100° C.) 
Sugar cookery (boiling point of water 
100° C.) 

Fondant 

Fudge frosting, boiled 

1 egg white to 1 cup sugar 

2 egg whites to 1 cup sugar... . 
1 egg white to 1 cup of dark 

brown sugar 

1 egg white to % cup of dark 
brown sugar, ^,4 cup white 
'Roasting of meat 

Temperature of oven 

First 15 minutes 

Remainder of time 

Temperature of meat interior 

Rare done 

Medium 

Well done 

Deep-fat frying. Temperature of fat for 

Uncooked foods 

Cooked foods 

Cold, wet, uncooked foods 

Baking. Temperature of center of oven 
for 

Sponge cakes 

Angel food cakes 

Souffles (surrounded by water) .... 

Bread 

Butter cakes 

Loaf 

Layer 

Muffins 

Parkerhouse rolls 

Baked potatoes 

Baking powder biscuit 

Popovers 

^Pastry 



Degrees 
Centigrade 



Degrees 
Fahrenheit 



-5 to -8 



3 to 10 

15 to 16 

26 to 40 

37 to 60 

(Depends upon acidity) 

Begins 56; completes 71 

82 to 99 

82 to 84 

89 to 94 

100 

103 



113 

111 

113 to 115 

117 



125 
122 



250 
175 

•±6.5 to 60 
60 to 70 
70 to 80 

175 to 190 
185 to 205 
190 to 195 



175 to 190 
150 to 170 

200 
180 to 220 

190 

210 
220 to 235 

235 

235 
235 to 240 
235 to 200 

240 



23 to 18 

32 
37 to 50 

60 

79 to 104 

98.6 to 140 

133 to 160 
180 to 210 
179 to 183 
192 to 201 

212 

185 



235 

232 

235 to 239 

243 

257 

252 



450 
347 

115.7 to 140 
140 to 158 
158 to 176 

347 to 374 
365 to 401 
374 to 383 



347 to 374 
302 to 338 

392 
356 to 428 

374 

410 
428 to 455 

455 

455 
455 to 464 
455 to 392 

464 



'Elizabeth Sprague and H. C. Grindley, "A Precise Method of Roasting 
Beef," University of Illinois Bulletin, Yol.'lY, No. 19. 

-Elizabeth Sprague, "Studies of Methods in Food Preparation," Journal of 
Home Economics, Vol. Ill, No. 5, p. 446. 



18 University of Illinois Bulletin [July, 

tory results have been obtained in sugar cookery on rainy days by first 
taking the temperature of boiling water and then raising the tempera- 
ture for the cooking of the sugar solution to accord. The lower tem- 
peratures given produce a softer frosting which requires more beating 
and hardens more slowly. The addition of egg white to a frosting or 
a candy will, it may be noted, raise the required temperature for the 
syrup. The larger amount of egg is often desirable as it makes a frost- 
ing which spreads easily and which keeps soft on the inside. The pres- 
ence of caramel raises the temperature to which sugar solutions should 
be cooked. Thus the soft ball test for dark broAvn sugar, which con- 
tains a considerable amount of caramel, is 119° C. instead of 113° C, 
as for white sugar. This applies in the making of boiled frostings, 
when dark brown sugar is used. The temperature required rises in 
accordance with the proportion of this sugar substituted. 

Cream whips best at 5° C, especially if it is not very thick. If 
the temperature is as high as 15° C. or 16° C, the butter-making point 
is reached and a little overheating gives a granular appearance and 
continued beating may produce butter. The proper temperature in 
the making of butter causes it to form much more readily and to give 
a larger bulk with a better color and consistency. 

The best quality of cottage cheese is made when the curd is sepa- 
rated from the whey by means of the sun 's heat or at a temperature of 
37° C, in a double boiler. However, the milk must be fairly acid to sep- 
arate at this temperature ; otherwise, it may be necessary to use a higher 
one. In any case, a double boiler should be used, and the temperature 
never allowed to go much above 70° C, as the curd will then toughen. 

Since eggs contain much albumin, the egg can be completely coagu- 
lated, even made firm, at a temperature of 71° C. or 72° C. At this 
temperature, the egg white is not made tough and rubbery as at higher 
temperatures. Hard cooked eggs are much more tender if cooked for 
forty-five minutes at 75° C. than if boiled for ten minutes. Likewise, 
soft cooked eggs are much better if cooked for five to ten minutes at 
about 75° C, than if boiled for three minutes. Approximately this 
temperature is obtained when eggs are put into boiling water and 
allowed to stand, with the heat turned off. 

Soft custards are thickened by means of egg and, on overcooking, 
curdle because the protein of the egg toughens and shrinks. The 
changes take place very rapidly, so that much care is required in the 
testing. The presence of egg white lowers the curdling point ; thus a 
custard made from egg whites curdles at 83° C, one made from whole 
egg at 83.5° C. and one made from yolks at 84.5° C. The optimum 



I^i7'] Cooking Temperatures 



19 



temperatures are: white custard, 82° C. ; whole egg, 82.5° C. ; and yel- 
low, 83.5° C. 

The roasting of meat is best accomplished by first searing over the 
meat at a high temperature and thereby retaining the juices. Also, the 
rich brown of meat which gives so desirable a flavor is not obtained 
below 249° C. After this brown coating is obtained, however, the tem- 
perature is reduced, as high heat continued for any considerable length 
of time toughens the protein of the meat and causes it to become dry. 
The old-time method of determining the length of time for a roast to 
cook, by allowing so many minutes to the pound, is not exact because 
the shape of roasts varies. A small chemical thermometer inserted in 
the roast does, however, tell exactly the condition of the meat and 
makes it possible to have a roast of any size or shape exactly as desired. 
In deep-fat frying, uncooked foods such as doughnuts require a 
lower temperature than foods which have been already cooked, as 
croquettes made of white sauce and cooked meat. The latter need only 
be warmed thru and browned, while the former must cook thor- 
oly before becoming too brown. Very large pieces of uncooked foods 
require lower temperature than do small pieces. Cold, wet, uncooked 
foods, as fish or French fried potatoes, are allowed a higher tempera- 
ture than other uncooked foods, particularly if prepared in large 
amounts, as they lower the temperature of the fat considerably. 

Bread rises best within the range of temperature given, 26° C. to 
40° C. A loAver temperature, even to freezing, will not kill the yeast, 
as it may be revived, but the activity is greatly retarded. Too high a 
temperature kills the yeast, so that no further action is possible under 
any conditions. 

Baking temperatures range from those of the slow oven, 150°- 
200° C, used for angel food, sponge cake, custards, and souffles, up to 
those of the hot oven, 230°-240° C, used for popovers, pastry, and 
biscuits. Size alters the required temperature, somewhat lower tem- 
peratures being used for large than for small cakes, and for bread than 
for rolls. The ingredients of a mixture also have much effect in deter- 
mining the required temperature. Any mixture lightened by eggs, as 
sponge cake or souffle, requires a lower temperature than does one 
lightened by baking powder, as biscuits, or by steam, as popovers. 

There are yet other possibilities in the use of a thermometer, and 
its proper use, accompanied by a working knowledge of the constituents 
of foods, will aid greatly in establishing more accurate methods and 
more uniform results. 



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